The present invention relates to a scanning probe microscope for observing the structure and conditions of the surface of a sample by a stylus, or more in particular to a microscope for scanning the sample while controlling the deflection of a cantilever holding the stylus. The invention further relates typically to an atomic force microscope or a microscope for measuring the distribution of various physical properties as well as observing the forms of the sample surface, or further to an apparatus having the ability to finely process the medium surface for information storage.
What might be considered the first arrival of a scanning probe microscope was the scanning tunnel microscope (STM) developed in 1983. Since then, a succession of apparatuses were suggested. These apparatuses operate in such a manner that various types of solid probes are brought to the proximity of the sample surface on the order of nm, and the structure and the properties of the sample surface are observed or measured with a resolution on the atomic order by the use of various physical phenomena. Among them, U.S. Pat. No. 4,724,318 (JP-A-62-130302) discloses an atomic force microscope in which a very small force (repulsive and attractive forces) exerted between the sample and the stylus at the forward end of a cantilever is kept constant, that is, the deflection of the cantilever is measured and maintained at constant level by servo control, while the sample is scanned and the surface thereof observed.
Further, an atomic force microscope comprising a mechanism for detecting by magnifying the deflection of a cantilever by the laser beam deflection method is disclosed in the Journal of Vacuum Science & Technologies, AS, Jan/Feb (1990), pp. 369 to 373.
Also, Applied Physics Letters Vol. 61, No. 8 (Aug. 24, 1992), pp. 1003 to 1005 presents an apparatus having an information write function for forming pits representing information in the surface of a sample on the principle of the atomic force microscope and by heating the forward end of the probe by infrared laser beam, i.e., an information storage apparatus as an application of the principle of the atomic force microscope.